Electro-osmotic extraction of water from animal, vegetable, and mineral substances.



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BOTHO SCHl/VERIN, 0F FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNGP. TOGESELL- SCHAFT IEI TR ELEKTRO-OSMOSE M. B. .H., 01' FRANKFURT-ON-THE-1VIAIN, GERMANY,

A CORPORATION.

ELECTRO-OSMOTIC EXTRACTION OF WATER FROM ANIMAL, VEGETABLE, AND MINERALSUBSTANCES.

No Drawing. Application filed November 20, 1912, Serial No. 732,546.Renewed October 24, 1917.

Specification of Letters Patent.

Patented May 1%, H918.

Serial To all whom it may concern Be it known that l, Bo'rno SCHWERIN, asubject of the German Emperor, and residing at Frankfort-on-thc-lllain,Germany, have invented certain new and useful 1mprovcments in the lllectrollsmotic Extraction of \Vater from Animal, Vegetable, andlilineral Substances, of which the following is a specification.

There are a large number of substances such as peat, clay, kaolin andthe like from which water cannot be entirely removed by mechanicalmeans, or only with extreme ditliculty.

The water can be extracted from such substances however on a commercialscale by elcctro-osmotic processes, generally used in conjunction withmechanical pressure.

In one known process the material subjected to osmotic action iscontained between the concentric walls of a cylindrical vessel, theinner wall forming the positive pole and the outer Wall the negative,the material passes through a worm revolving between the electrodes, andin order that there should be good contact between the electrodes andthe particles, the latter can only escape, when they exert sufiicientpressure to open the exit orifice against the action of a spring. Inanother arrangement the material flows between two conveyor bands, theelectrodes being intermittently moved toward each other, so as to pressagainstthe material, or boxes attached to an endless band are used. thebottom of the boxes being connected with one pole, while the other poleis connected with covers fitting the boxes and pressed onto thematerial. In another method the apparatus is arranged in a verticalstage, in which tiers of boxes are placed one above the other andpressure is exerted on the material by movable electrodes. In all theseconstructions, which are intended for substances in a state of pulp, theelectrodes are movable and serve at the same time as plates for applyingpressure to the material, or pressure is eXerted on the movingparticles.

According to the present invention neither the electrodes nor theparticles of the material in the compact condition are moved. The methodemployed in the present invcntion is to place, in a space of constantvolume, the substance from which water is to be extracted, thissubstance being acted upon by an electric current and pressure orsuction exerted or transmitted by the substance itself.

The electrode toward which the water migrates is constructed in knownmanner so that the water can flow off.

The electrodes are preferably made of hard lead and arranged behind thefilter cloth of a filter press. During the electr0- osmotic process thesubstance is pumped in under slight pressure, according to the amount ofwater removed, until the coinpact mass left has attained the desireddegree of dryness. Then after the current has been switched off and thehydraulic pressure released, the press is emptied in the usual manner.

Filter presses of previously known construction have Worked fairlysatisfactorily as long as the solid particles in suspension arecomparatively large grained. But they operate less and lesssatisfactorily and with increasing expense. the finer the particlesbecomc and when the colloidal size of particles is reached these filtersare quite impossible, since as the degree of fineness of the particlesincreases, the pressure used must becorrespondingly increased. and asthe pressure increases more filter cloths are used up and more energy isexpended.

lVith the present method only a very small pressure is required comparedto that usually employed. ll 'hereas in previously known methodspressures up to 20 atmospheres have been necessary, with the presentmethod the pressures may be reduced, even to 1 atmos phere. and undercertain conditions suction may be used instead.

Also when working according to the present method, at the electrodetoward which the water migrates. that is generally at the cathode ornegative electrode. substances, such as peat and clay, chalk. ferrichydro- 'oXid and other substances. separate out,

which gradually prevent the water from passing out or choking thefilter. This disadvantage ean be obviated by reversing the flow ofcurrent after each or several charges. The deposited substances are thenfreed 01' Q we migrate in the opposite direction into the cakes ofcompressed material and are re lnOYGd with these.

The method is especially suitable for colloids in suspension such asclay, dyestuffs and the like.

Having now particularly described and ascertained the nature of my saidinvention and in What manner the same is to be performed, what I claimis:

l. The method herein described which consists in subjecting material insuspension to the action of an electric current While subject topressure exerted by said material confined Within a space the capacityof which remains constant, and maintaining the suspension free fromdisturbance.

'2. The method herein described 7 which consists in pressing material insuspension in a filtenchamber of constant volume, maintaining thesuspension free frorn'disturbance, causing a continuous electric current to pass through the mass confined in the chamber, and passing theliquid through filter-cloths and perforated electrodes fixed in the saidchambers.

3. The method herein described which consists in pressing material insuspension in a filter-chamber of constant volume, maintaining thesuspension free from disturbance, causing an electric current to passthrough the mass confined in the chamber, allowing the liquid to How offthrough filtercloths and perforated electrodes fixed in the saidchambers, and changing the direction of the electric current atintervals, for free ing the filtering devices.

BOTHU SCH-WERIN.

"Witnesses JEAN GaUND, CARL German.

